The Collaborative International Dictionary of English v.0.48:

Hyperbolically \Hy`per*bol"ic*al*ly\, adv.
   1. (Math.) In the form of an hyperbola.
      [1913 Webster]

   2. (Rhet.) With exaggeration; in a manner to express more or
      less than the truth. --Sir W. Raleigh.
      [1913 Webster]

WordNet (r) 3.0 (2006):

hyperbolically
    adv 1: in an exaggerated manner [syn: hyperbolically,
           exaggeratedly]